Labview hangs when quering instruments

[crown7]

I am connecting to two Keithley DMM6500 through USB and build a VI that reads DC voltage each secon. It work perfectly before, but now it takes 5-10 minutes before i get a measurement. Often i only get measurement from the one instrument, and then a crash.

Also communication with a DC powersupply through a NI GPIB PCI card in the PC does not work anymore.

[altenbach]

What has changed since "before"? (code change? hardware change? driver update? bad cable? etc.)

Can you define your vague statement of "does not work anymore"?

[Kyle97330]

Could you switch from using USB to using Ethernet? The DMM6500 supports both.

If you're experiencing a real "crash", like you get one of those angry Windows popups like "Access violation" or similar, that could be related to the USB drivers in use and you can bypass that using Ethernet instead.

But also just in general you need to add a lot more details, starting with Altenbach's questions.

[crossrulz]

I tend to just avoid USB for communications for a large range of reasons. But the fact your PCI GPIB card does not work either makes me think something happened to your VISA driver. I would repair your VISA and NI-488.2 drivers and try again.

As previously stated, if you can use Ethernet, I would use that instead of USB.

[crown7]

Perfectly agree, very vague error description. Sorry for that

When i start the VI LV goes into running mode, but nothing else happens. I see no reaction on the instruments. After 3-5 minute ocatinally i get one reading from the one instrument, but most often nothing, and i have to force Labviev closed by windows taskmanager.

The only change i recall made to my system was upgrade of Audio Precission APx500 software from version 9.0 to the lates version 9.1.

I am now repairing everything from within NI package manager, but i just ran into some issues with aplications from WELLER (WFE Monitor 4.2 and WX Minitor 1.15) I will try to uninstall the WELLER aplications and rool back the Audio Precission software and see if it helps. 

This could be related to some VISA components at least.

[crown7]

By The way, both Keithley DMMs works flawless with the "KickStarter" software from tektronix that came with the Keithleys. And through USB drivers

[cstorey]

USB & GPIB not working points to driver or coding issue. Seeing some code might help.  Also any error messages.  

Are you running in Highlight Executuion mode so you can see where the code hangs?

Make sure all instruments have reasonable timeouts of say 1-10s so you get some error feedback quickly rather than waiting 3-5mins for a measurement.  

Craig

[crown7]

Trying to repair my installation from NI Package Manager i get this error. I have uninstalled the WELLER application and rebooted. The WELLER application is not on the list anymore, but Package manager keeps asking for the location of the distribution. The WELLER applications were installed from a RARarchive, and i do not have that anymore. Since i cannot find the location, the only option from here is to exit the repair without any changes.

How du i complete the repair?

[Yamaeda]

If you're communicating via TCP/IP it could be a firewall problem, that's quite common.

[crown7 · Accepted solution]

Fianlly I got this solved.

Turned out that i had updated som Tektronix tools and at the same time upgraded some TekVISA components and OpenChoice applications

The rootcause was that apparently i had two active Visa applications running simultaniously. both National Instruments VISA and Tektronix VISA was enabled in OpenChoice VISA64 Conflict Manager

The solution was to select only National Instruments VISA, by removing the checkmark in Tektronix VISA

Everything is back to normal 🙂